Our overall objective centers on understanding the electronic properties of porphyrin molecules with the aim of elucidating the physical mechanisms behind porphyrin biological activity. There are six specific types of work: (1) experimental study of optical absorption and luminescence spectra, and theoretical study of the energy levels of exotic metal porphyrins; (2) study of fast kinetic processes involving transfer of an electron from a porphyrin; (3) study of the optical and electronic properties of vapor deposited porphyrin films with the aim of understanding exciton and electron transfer processes; (4) study of the triplet state by optically detected magnetic resonance; (5) study of porphyrin dimer systems; (6) theoretical study of ligand binding both in iron and related metal complexes. BIBLIOGRAPHIC REFERENCES: "Absorption and Emission of Thin Solid Films of Octaethylporphin," J.S. Bonham, M. Gouterman, and D. B. Howell, J. Luminescence, 10, 295 (1975).